1. Technical Field
The present invention relates to a wiring base and an electrical connection box using the same.
2. Related Art
A wired assembly for an electrical connection box is known that includes a wiring base and a wire arranged thereon. Japanese provisional patent publication no. 2001-286038 discloses a method for manufacturing a wired assembly in which, as shown in FIG. 15A, a wire 7 to be arranged on a wiring base B is fed from a wiring head 6, with a wiring base B rotated around its rotation axis together with a holder (not shown) supporting the same and with a wiring head 6 moved along the rotation axis of the wiring base. As a result, the wire 7 is wound on the wiring base B, with the desired wire portions received in corresponding ones of wire grooves formed in the wiring base. Although a detailed illustration is omitted, the wire 7 is thereafter cut off at its desired portions, and connecting terminals are forcibly inserted into corresponding ones of terminal grooves that are formed in the wiring base so as to communicate with the desired wire grooves, whereby the connecting terminals are electrically connected to a conductor of the wire, thus completing the fabrication of a wired assembly. By connecting electrical components to the connecting terminals through connectors, an intended electrical circuit is attained.
A wiring pattern (i.e., the wire-cutting positions and terminal-insertion positions) in the wired assembly varies depending on specifications of the electric circuit to which the wired assembly is applied. To some extent, a conventional wired assembly can comply with the varying wiring pattern by changing wiring and terminal insertion programs, in accordance with which a wiring apparatus is operated. However, when the required number of wire grooves or terminal grooves to realize the desired wiring pattern exceeds the number of grooves actually formed in the wiring base, there occurs a problem of an additional wiring base being required to eliminate shortage of grooves. Contrary to this, when the required number of grooves is considerably less than the grooves formed in the wiring base, most of the wire grooves or terminal grooves formed in the wiring base are not used to realize the desired wiring pattern. Thus, there occurs another problem of the wiring base to realize the desired wiring pattern being excessively large in size, resulting in an oversized electrical connection box.
As for a connecting terminal that is generally formed into a crank shape, it can buckle while being mounted with a connector after the connecting terminal is inserted into a terminal groove of the wiring base.
Moreover, during the operation of laying a wire 7 on the wiring base B while rotating the wiring base around its longitudinal axis together with a holder (not shown) supporting the same, a wiring head 6 is caused to rotate when it interferes with the wiring base, to thereby permit further rotation of the wiring base so that the wiring operation can be continued (see FIGS. 15A and 15B). With the conventional arrangement shown in FIGS. 15A and 15B, however, the wire 7 fed from the wiring head 6 starts being accommodated in a wire groove Ba of the wiring base B only after the wiring base rotates for a considerable angle from when it is in line- or point-contact with the wiring head 6. In this manner, the wiring head 6 rotates for a large angle relative to the wiring base B from when it becomes in contact with the wiring base to when it starts being accommodated in the wire groove Ba, and hence the distance between a wire feed port of the wiring head and the wire groove increases. Further, the wiring head is initially in line- or point-contact with the wiring base, and is hence liable to be deviated in the longitudinal direction of the wiring base due to a lateral force acting thereon in the longitudinal direction. Thus, the wire 7 tends to be dislocated from the wire groove Ba in which it is to be received. Such a phenomenon becomes noticeable at higher wiring speeds, and as a result the wire fed from the wiring head can be dislocated from the wire groove, making it difficult to carry out an accurate wiring operation.
To obviate this, the wiring speed is heretofore lowered to suppress the positional deviation of the wiring head. However, a low wiring speed requires a prolonged period of time for fabrication of the wired assembly. In order to complete the fabrication of a desired number of wiring assemblies within a prescribed period of time, an increased number of wiring apparatuses are required to operate simultaneously. This entails a problem of increased fabrication costs of wired assemblies and electrical connection boxes using the same.
An object of the present invention is to provide a wiring base that is capable of easily complying with the change in a wiring pattern in accordance with which a wire is to be laid on the wiring base.
Another object of the present invention is to provide a wiring base that is capable of preventing a connecting terminal from buckling when a connector or the like is mounted thereto.
A further object of the present invention is to provide a wiring base that permits a wire to be properly laid on the wiring base even at a higher wiring speed, thus shortening a period of time required for the wiring to thereby reduce fabrication costs.
Still another object of the present invention is to provide an electrical connection box using the aforementioned wiring base.
According to a first aspect of the present invention, there is provided a wiring base molded from an electrical insulating material. The wiring base comprises: a base body extending along a longitudinal axis of the wiring base; wing portions formed on an outer periphery of the base body so as to be circumferentially spaced apart from one another; and coupling portions individually formed in opposite end faces of the base body, each wing portion being formed with wire grooves that individually open to an outer face of the wing portion.
As mentioned above, the wiring base according to the first aspect of this invention, having a coupling portion at each end face thereof, is capable of being coupled with one or two other wiring bases of the same construction as the first-mentioned wiring base. In other words, a wiring base group can be easily constituted by one or more wiring bases. Such a wiring base group makes it easy to comply with the change in the desired number of wire grooves or terminal grooves required to realize an intended wiring pattern, thus contributing to realization of an intended electric circuit.
A wiring base according to a second aspect of this invention comprises: a base body; wing portions formed on an outer periphery of the base body; and a reinforcing plate mounted to a mounting groove that is defined between adjacent ones of the wing portions and that extends along the longitudinal axis of the wiring base. The wing portions are formed with wire grooves and terminal grooves that are in communication with desired ones of the wire grooves. Each terminal groove extends across a corresponding wire groove in the direction of the longitudinal axis of the wiring base, and is arranged to be inserted with a connecting terminal. The reinforcing plate supports connecting terminals individually inserted into corresponding terminal grooves.
With the wiring base according to the second aspect of this invention, connecting terminals inserted into terminal grooves of the wiring base are supported by the reinforcing plate when connectors or the like are mounted to the connecting terminals, thereby preventing the connecting terminals from buckling.
A wiring base according to a third aspect of this invention comprises: a base body; wing portions formed on an outer periphery of the base body; and guide portions respectively formed integrally with the wing portions so as to project circumferentially from the wing portions. Each guide portion is formed with wire guide grooves that open to an outer face of the guide portion and are in communication with the wire grooves, respectively. Each guide portion has a flat outer face thereof extending at an acute angle relative to a boundary face between the guide portion and a corresponding wing portion.
In an operation of laying a wire on the wiring base, a wiring head may be employed that is arranged to returnably rotate with respect to a head support and disposed to interfere with the wiring base.
With the wiring base according to the third aspect of this invention that includes guide portions each having a flat outer face thereof extending obliquely with respect to a corresponding wing portion and having wire guide grooves individually communicating with wire grooves, an angle of rotation of a wiring head from when the outer face of a guide portion interferes with the wiring head to when the wire starts being accommodated in a desired wire groove through a wire guide groove is suppressed to be small, suppressing the increase in the distance between a wire feed port of the wiring head and the desired wire groove. Also, a positional deviation of the wiring head due to a lateral force applied to the wiring head is suppressed. The flat outer face of the guide portion immediately establishes a face-contact with the wiring head, contributing to a suppressed positional deviation of the wiring head. As a result, even at a higher wiring speed, the deviation of the wiring head in the longitudinal direction of the wiring base is suppressed, and the wire fed from the wiring head is prevented from being dislocated from a wire groove in which the wire is to be received, making it possible to carry out the wiring of the wire on the wiring base with accuracy in a short time, whereby a wired assembly comprised of a wiring base and a wire wound therearound can be manufactured at low costs.
An electrical connection box according to a fourth aspect of this invention comprises: a wired assembly, having a wire base group which is comprised of one or more wiring bases according to the first, second, or third aspect of this invention and on which a wire is laid; and a casing accommodating therein the wired assembly.
According to the fourth aspect of this invention, by using one or more wiring bases according to the first aspect of this invention, a wiring base group for realizing an intended wiring pattern suitable to specifications of an electric circuit for the connection box can be constituted by a minimum number of wiring bases, making it possible to obtain an electrical connection box that is compact in size. By using a wiring base according to the second or third aspect of this invention, an electrical connection box can be effectively manufactured at low costs, while preventing connection terminals from buckling or while permitting respective portions of a wire to be accurately accommodated in the desired wire grooves of the wiring base.